WASHINGTON (CBS DC) – The International Space Station is still having trouble with a coolant system, months after a spacewalk was supposed to fix the problem.
NASA stresses that the six astronauts on board are not in any danger.
The station uses two cooling systems that pump ammonia through pipes on the outside of the orbital platform to prevent electrical systems from overheating and control the temperature inside.
A valve in Coolant Loop A malfunctioned, which prompted flight controllers to power down nonessential equipment in the forward part of the lab complex.
The ammonia is still circulating, but it cannot dissipate heat into space, says NASA.
“The ETCS (External Thermal Control System) Loop A is still running, but the flow control valve doesn’t appear to be positioning properly,” a flight controller radioed the crew. “So the Loop A is very cold. We’re not expecting it to get warm enough for us to be able to reintegrate for heat rejection.”
Coolant Loop B is functioning, but it is unable to serve the entire station, so nonessential systems were powered down, including parts of the research laboratory.
Since that means there is no backup system, NASA is very anxious to fix the problem as soon as possible.
Engineers on the ground are evaluating data and trying to troubleshoot the system.
If they cannot find a solution, astronauts may have to undertake a spacewalk to replace the faulty valve.